Sounds a lot like her studio version, so either she's damn good live or faking it. Hard to tell with a vid of such horrible quality.
I really hope it's all talent though, she was my hero back in her Parent Trap days lol (HOLLYWOOD NEEDS MORE REAL FRIKKIN REDHEADS).

She was singing Karaoke .
The more pressing question would be why would she be grabbing her crotch while singing at a politicians's party? It's embarrassing.
No class. Ya just can't take her anywhere.Put that away Lindsay.